Respiratory viruses can infect any age group although the severe complications of such infection are often restricted to children and the elderly. These viruses are most commonly transmitted by airborne droplets or nasal secretions and can lead to a wide spectrum of illness. In the UK many of these viruses are seasonal in their activity and tend to circulate at higher levels during the winter months.

• Influenza
• RSV
• Human parainfluenza viruses (HPIVs)
• SARS
• Adenovirus
• Novel coronavirus (September 2012)